Association between neurodevelopmental impairments and motor function in Duchenne muscular dystrophy

Area of Science:

• Neurology
• Genetics
• Pediatrics

Background:

• Duchenne Muscular Dystrophy (DMD) is a progressive genetic disorder affecting motor function.
• Prognostic factors for motor outcomes in pediatric DMD populations are crucial for clinical management.
• Corticosteroid treatment is common, but understanding outcomes in naive patients provides a baseline.

Purpose of the Study:

• To investigate prognostic factors for motor outcomes in corticosteroid-naive boys with Duchenne Muscular Dystrophy (DMD).
• To examine the associations between neurodevelopmental concerns, DMD mutation location, and specific motor function measures.

Main Methods:

• A cohort of 196 corticosteroid-naive boys aged 4 to <8 years with DMD was studied.
• Parent-reported data on speech delay, speech and language difficulties (SLD), and learning difficulties were collected.
• Motor outcomes assessed included 6-minute walk distance (6MWD), North Star Ambulatory Assessment (NSAA) total score, 10-meter walk/run velocity, and rise from floor velocity.

Main Results:

• Participants with SLD showed a significantly reduced 6MWD compared to those without.
• Distal DMD mutations were associated with slower 10-meter walk/run and rise from floor velocities.
• Learning difficulties correlated with lower NSAA total scores and reduced 6MWD, particularly in those with distal mutations.

Conclusions:

• Distal DMD mutations and learning difficulties may negatively impact motor performance in DMD.
• The presence of neurodevelopmental symptoms should be considered when evaluating motor outcomes in boys with DMD.
• Further research is needed to confirm these findings and their clinical implications.